1. Department of Bioresource and Agrobiosciences, Graduate School of Science and Technology, Kobe University, 1–1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657–8501, Japan
2. Department of Animal Science, Graduate School of Science and Technology, Kobe University, 1–1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657–8501, Japan
3. Department of Based Veterinary Medicine, College of Veterinary Medicine, Inner Mongolia Agricultural University, 306 Zhaowuda Road, Huhhot, Inner Mongolia 010018, P.R. China
4. Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1–1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657–8501, Japan
5. Department of Veterinary Laboratory Animal Science, Faculty of Agriculture, Tottori University, 4–101 Koyama-cho Minami, Tottori, Tottori 680-8553, Japan
6. Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, 1750–1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761–0793, Japan